Make noise with a piezo buzzer. Use a pwm pin.
Dependents: Cave_Runner popcorn default USBMIDI_Buzzer ... more
beep.c
- Committer:
- dreschpe
- Date:
- 2011-02-01
- Revision:
- 2:a34405c20cf5
- Parent:
- 0:18e4a9c978ec
- Child:
- 3:5a8242af60ba
File content as of revision 2:a34405c20cf5:
#include "beep.h" #include "mbed.h" /** class to make sound with a buzzer, based on a PwmOut * The class use a timeout to switch off the sound - it is not blocking while making noise * * Example: * @code * // Beep with 1Khz for 0.5 seconds * #include "mbed.h" * #include "beep.h" * * Beep buzzer(p21); * * int main() { * ... * buzzer.beep(1000,0.5); * ... * } * @endcode */ using namespace mbed; // constructor /** Create a Beep object connected to the specified PwmOut pin * * @param pin PwmOut pin to connect to */ Beep::Beep(PinName pin) : _pwm(pin) { _pwm.write(0.0); // after creating it have to be off } /** stop the beep instantaneous * usually not used */ void Beep::nobeep() { _pwm.write(0.0); } /** Beep with given frequency and duration. * * @param frequency - the frequency of the tone in Hz * @param time - the duration of the tone in seconds */ void Beep::beep(float freq, float time) { _pwm.period(1.0/freq); _pwm.write(0.5); // 50% duty cycle - beep on toff.attach(this,&Beep::nobeep, time); // time to off }